From the Desk of Andrew Hine
Project Engineer:

IA OWTS What are they and do I need one?

I recently had a conversation with a friend who was looking to replace his home’s sanitary system and I found myself answering a bunch of questions that I deal with on a daily basis as an engineer. I later realized that other people may be asking themselves these very same questions without knowing where to go for answers. I am writing this post to provide information to the average homeowner that may need a new sanitary system for their home but still has questions.

Q: I’m building a new house/renovating my existing house and I am being required to install an IA-OWTS system. What does IA-OWTS stand for? What are the steps involved in getting an IA OWTS system approved and installed?

IA-OWTS stands for Innovative Alternative On-site Wastewater Treatment System and is in essence a personal treatment system for your house’s wastewater. Some areas on Long Island are serviced by a sewage treatment plant which treats wastewater by removing nitrogen. However, many of the properties on Long Island, primarily Suffolk County, are not connected to a sewage treatment plant and instead are serviced by their own on-site septic system; in the past typically cesspools were used. We are now in the process of replacing these cesspools with IA-OWTS systems.

Q: Well, why can’t I just use a cesspool as my sanitary system? Why are we making the change?

Cesspools were not designed to remove nitrogen from wastewater and this nitrogen has been making its way to our groundwater and other surface waters such as our beaches, bays, lakes and rivers. IA-OWTS systems are designed to greatly reduce nitrogen before allowing the wastewater to leach back into the ground, reducing nitrogen pollution. Why should you care about nitrogen getting into our water? Nitrogen pollutes our water and causes a decrease in water quality and can also cause harm to our environment.

Q: Well, how does this IA-OWTS system remove nitrogen in the wastewater?

Chambers in the IA’s septic tanks create an environment where natural bacteria, or “bugs”, can grow and breakdown waste to create energy for themselves, which in turn reduces the nitrogen in the wastewater. The wastewater is then allowed to exit the septic tank, enter a leaching pool, and dissipate into the ground (with a much lower concentration of nitrogen than when it leaves your house).

Q: Okay well that sounds great for the environment but what about my wallet? How much do these IA-OWTS systems cost?

There are a few costs associated with installing these sanitary systems. The initial cost is in preparing the sanitary design (which needs to be done by a licensed engineer or surveyor) and having the health department review and approve said design. Next there is the cost of the installation, hookup, and inspection of the system. Finally, annual maintenance is required for an IA-OWTS system to make sure everything is functioning properly and the nitrogen eating bacteria are doing their job. Luckily there are grant programs that are in place to help the average homeowner get one of these systems installed without having to file for bankruptcy.

I hope this has given you some useful information on IA-OWTS systems and answered your questions on why Long Island is moving towards having these systems installed. If you have any questions, including pricing and applicability, please don’t hesitate to contact us by phone at 631-234-2220 or send me an email at


Andrew Hine
Project Engineer
J.R. Holzmacher P.E., LLC